Please report all issues at https://github.com/hashcash/wordpress-hashcash/issues

Because of the way plugins work, problem might arrise from specific combination of WP version, plugins, themes.
Therefore for the best result everytime you submit a bug report or just seeking an advice please include following:

Version of WordPress you are using

Brand and version of Browser you are using to test it

List of third-party plugins and their versions activated on your website

What theme and version you are using

Protect Against Web Spam

Typically various “Internet SEO Companies” try to leverage poor forum software protection against mass submission and create many worthless posts with links to a website they are promoting.

Some forum and blog software implement various CAPTCHA solutions but these have two negative aspects:

They annoy your visitors.

They provide a fake sense of security.

Today it is possible to buy access to API which solves any kind of CAPTCHA for just $0.70 per 1000 CAPTCHA images solved by a real human being. And do you really think your customer will be happy to try to solve one of these ridiculous CAPTCHAs?

Secure Against Brute Force Attacks

Many modern applications are susceptible to brute force attacks. Take a typical login form, for example. Hackers can compromise account security by trying every possible password combination. They can also leverage a large network of proxy servers to paralelize this attack. Forcing their browser to work hard makes it too expensive and slow for hackers to perform a brute force attack.

Based On Open Technologies

We leverage the following features:

Asm.js

HTML5

Web Workers

Browsers supported:

Google Chrome 28+

Mozilla Firefox 22+

Internet Explorer 10+

Opera 18+

Fully translatable

All strings are available for translation

Fully accessible

We follow both common sense and accessibility guidelines to make this
widget accessible to people with limited abilities. We make it focusable
and actionable via Tab-Enter keys, as well as we have WAI-ARIA live region
which updates blind user via screen reader about progress.

Screenshots

Submit button disabled. User need to unlock it before proceeding.

Widget updates both visually and via WAI-ARIA to inform user about progress.

Submit button unlocked.

If user tries to click on submit button before unlocking, information popup will show up.

Installation

Download plugin folder into /wp-content/plugins/ on your server

Activate the plugin through the ‘Plugins’ menu in WordPress

On Hashcash plugin settings page generate new keys and save settings

Contributors & Developers

“Hashcash” is open source software. The following people have contributed to this plugin.